West German Patent No. 3,412,169 shows typical prior art of the general type to which the present invention relates. This patent shows a tension roller with a thin-walled roller shell of metal wherein one of the end sections is folded over and forms a rearward facing sleeve in the bore having an edge against which the bearing ring of the roller bearing abuts. Radial projections facing the lateral surface of the bearing ring are formed on the opposite sie of the sleeve. Even though this arrangement provides a good attachment between the bearing ring and the roller shell, the roller shell and elements project axially in both directions a considerable extent. This arrangement is designed for a relatively wide drive belt. Even though the tension roller functions generally satisfactorily, there are ways in which the production of this type of assembly can be made more economical. It has been found that production of these assemblies is rather costly and could be improved from an economic viewpoint. For example, formation of the folded-back end section involveds complicated, intricate procedures. It has been found that when this section is omitted and the bearing ring is simply attached by means of radial projections formed on both ends, the bearing ring must be positioned precisely to prevent the roller shell from wobbling and to provide the necessary axial symmetry of the entire unit. This is possible only when additional positioning devices are used for installation. Furthermore, relatively thin-walled roller shells present problems if they are not provided with outward facing flanges to stabilize them. In these instances, the flanges must face inward to provide the reinforcement of the edge areas. This rather complicated arrangement hinders the use of tools needed to form the radial projections for installation.